1. Field of the Invention
This invention relates to novel 5-fluorouracil derivatives useful as an anti-cancer or anti-tumor agent. More particularly, this invention relates to 5-fluorouracil derivatives represented by the formulae: ##STR2## wherein R.sub.1 represents an aryl group having 6 to 10 carbon atoms and R.sub.2 represents an alkyl or alkenyl group having 9 to 23 carbon atoms.
2. Description of the Prior Art
5-Fluorouracil is a compound which inhibits the formation of nucleic acids in a living body by its metabolic antagonism, and, therefore, is useful as an anti-tumor agent. 5-Fluorouracil has been employed in the form of 1-N-substituted derivatives thereof, for example, the 1-N-tetrahydrofuranyl derivatives. However, the tetrahydrofuranyl group at the 1-N-substituent is a specific group and the industrial production thereof involves high costs. Other 1-N-substituted derivatives which have hitherto been proposed include 1-N-acetyl-5-fluorouracil (see U.S. Pat. No. 3,041,335), 1-N-benzoyl-5-fluorouracil (see Gann, 65, 463, 1974) and 1,3-di-N-benzoyl-5-fluorouracil (see West German Patent 2,455,423). However, 1-N-acetyl-5-fluorouracil is highly toxic, 1-N-benzoyl-5-fluorouracil cannot be synthesized on a reproducible basis, and 1,3-di-N-benzoyl-5-fluorouracil does not show reproducible activity.